5 chains merged

"I passed by Allah's Messenger (S) while he was performing Salat, so I said greeted him with Salam, and he returned it by making signals." He said: "I do not know except that he said: 'He indicated with his finger.'"

I passed by the Messenger of Allah (ﷺ) who was praying. I saluted him and he returned it by making a sign. The narrator said: I do not know but that he said: He made a sign with his finger. This is the version reported by Qutaybah.

"I passed by the Messenger of Allah (ﷺ) when he was praying, and greeted him with Salam. He returned my greeting with a gesture, or maybe it was just with his finger."

He greeted the Messenger of Allah (ﷺ) with the Salam when he was praying, and he returned the greeting.

"The Messenger of Allah (ﷺ) sent me on an errand then I came back to him while he was praying. I greeted him with the salam and he gestured to me. When he finished he called me and said: 'You greeted me with Salam just now and I was praying